AMAZON ADVENTURE: A CASE STUDY IN MEDICAL TECHNOLOGY AND BIOETHICS
Bobbi Swain and John Nishan
Woodrow Wilson Biology Institute
In this exercise you will test your
problem-solving skills, your ability to see connections, and your
ability to draw conclusions and inferences from information provided
in this case study. The case involves some of these ideas:
- medical technology - using organisms and biological processes to aid in the treatment of human disease or disorders.
- epidemiology - the investigation of the causes and spread of diseases.
- pharmacology - the study of the origin, extraction, and use of drugs.
- bioethics - examining the risks, benefits, and consequences of biological research and application in order to establish priorities and conditions for the survival of the global ecosystem and its human inhabitants.
- ethnobotany - the use of plants and their properties in relation to a culture or group of people.
Joy Rhodes and her husband, Fred,
are pharmacologists and epidemiologists and have been "prospecting"
(searching) for and developing drugs for many years. Although
their previous work had been in Africa, they have decided to make
a trip to the Amazon rain forest at the suggestion of Barbara
Morgan, an anthropologist whose parents worked as missionaries
in the area for 25 years. Barbara has found a village of people
called the Iboti, who have had little or no contact with the modern
On the visit in 1985, Joy and Fred
communicate with the Iboti using Barbara to translate the language.
In the village, many of the people are ill with a disease they
call akalua hisbanani, roughly translated to mean "that
which weakens the body and drains it of fluids" or "wasting
sickness." The disease is not new to the Iboti. Chills,
fever, diarrhea, vomiting, fatigue, and a rash across the abdomen
are the symptoms. For many years, it has been successfully treated
with a tea made by boiling the leaves of the noa tree. Joy and
Fred decide to take blood samples to investigate the cause of
the disease since symptoms indicate that it is probably viral
or bacterial in origin. They take leaf samples from the noa tree
as well as many other specimens identified by the natives as having
medicinal applications. They carefully record the names of the
plants, the parts used, and the particular ailments treated.
They take plant specimens and blood
samples to the United States where Joy and Fred work at Baltimore
University Hospital with grants from Phillips Pharmaceuticals,
the National Institutes of Health (a federal agency) and Colco
yourself in the role of one of the investigators. You now have
frozen leaf samples and blood samples in the laboratory. List
some of the initial procedures or experiments that you would undertake.
(5 - 10 minutes)
Group: Share your
list of initial procedure with members of your group. Work together
to combine your lists to be shared with the rest of the class.
Class: Each group
shares its lists so that similarities and differences can be noted.
(Remainder of period)
Joy and Fred have identified six isolates
from the "chemical tea" extract from the noa plant
leaves. A chart appears below. In addition, they have classified
"wasting sickness" as viral in origin and have tentatively
named it wasting sickness virus or WSV. A picture of the virus
is shown below:
Table of Noa Leaf Chemical
|Pathogenor Cancer Cells||Isolate|
|Staphylococcus aureus|| - || - || - || - || - || -|
|Hepatitis B Virus (HBV) || + || - || - ||
- || - || -|
|Mumps Virus || - || - || - || -||
- || -|
|Breast Cancer || - || - || - || + ||
- || -|
|Prostate Cancer cells || - || - || - || - ||
- || -|
|Herpes Virus || - || - || - ||
- || - || -|
|Wasting Sickness Virus (WSV) || + || - || - ||
- || - || -|
| + stops growth|| - no effect on growth|
What conclusions or inferences can be made form the table and
information given above? An inference is an idea which seems
to be implied in the results but was not tested or observed directly.
An inference can become a hypothesis for a later experiment.
- Joy and Fred decide to pursue isolate
A as a treatment for Hepatitis B. What would be the next steps?
- HOW should the drug be obtained?
What benefits and problems are associated with growing the
plant natively versus growing it in another country? Also,
what factors need to be considered when planning to build a facility
to extract the active ingredient(s) from the leaves? Is there
an alternative to the extraction process?
- If Phillips Pharmaceuticals
gets FDA approval to market the drug, what environmental and
ethical issues should be considered?
Consider the following scenario which
might have occurred. Joy and Fred Rhodes find that the treatment
of "wasting sickness" contributes to an increased incidence
of miscarriages due to one of the other active ingredients which
is not related to the treatment of "wasting sickness."
The high rate of miscarriages occurs in those women who took
the plant remedy when they were children. Apparently the active
ingredient stays in the system of these children and manifests
its presence when they reach childbearing age. It (the chemical)
contributes to low overall birthrate and a problem with the social
status of the woman's husband . The tribe values children and
a family with only a few children is not considered to be blessed
by their God. Furthermore, none of the other isolates identified
by Joy and Fred has been found to have any significant value in
treating or curing other global diseases or cancers.
- Should the scientists allow the
natives to use the plants, knowing that it contains an ingredient
not necessary to cure the "wasting sickness" but contributing
to the abnormally high incidence of miscarriages?
- Consider that "wasting sickness"
does not afflict people outside of this particular region. What
if, in working to synthesize the isolate artificially, the Phillips
Pharmaceutical Company determines that it is unprofitable for
them to manufacture this drug on a small scale, and the demand
is not large enough to mass produce the drug. Should they still
produce this drug, knowing that it will help the Iboti? Do they
have a moral obligation to do this?
- The use of plants is commonly tied
to religious practices. Suppose this plant is used by the religious
leaders of this tribe. When prepared in a different way and used
as part of a religious ceremony the leaf extract is found to cause
a strong predisposition to another ailment, such as colon cancer
or kidney failure. Should the tribe leaders be encouraged or
forced to stop the use of the plant?
Questions for Further Thought
- The term "serendipity"
is relevant to this situation. Look up its meaning and suggest
why it applies to this case, particularly in relation to the isolates
produced from the original "tea." Can you cite other
examples of scientific serendipity?
- What precautions should be taken
by scientists visiting the tribe to ensure that pathogens uncommon
to this area are not introduced into members of this tribe? And,
if pathogens are introduced into the tribe, what responsibilities
should the scientific community have to treat the diseases which
have been introduced?
Diamond, Jared, "The Arrow of
Disease", Discover, October, 1992.
World Resource Center, May, 1993.
Teacher Outline for Presentation of Activity
This exercise is designed to be a beginning activity for the
first day or two of classes. It can also be used as a problem-solving
activity at other points.
It is suggested that you provide a
diagram of a virus to represent WSV or "wasting sickness"
virus. This can be a modified one of hepatitis B virus since
the case data indicate that they are similar. A map of South
America would be helpful to show the location of the Amazon.
It is also recommended that you view
the National Geographic film "Secrets of the Amazon"
to get background for this exercise. It portrays the work of
Walter and Memory Lewis, whose experience provided the basis for
this hypothetical model. It can be shown to students at the end
of the activity. Some possible responses are given for Parts
One and Two. This list is not meant to represent the full range
of responses. The questions in the student guides are intentionally
broad. Due to the nature of the Questions in Part Three, no responses
- Boil the leaves according to instructions
provided by the natives.
- Analyze the tea for chemical content;
and categorize the components.
- Test each ingredient on some known
viral and bacterial pathogens.
- Isolate pathogen or disease agent
from blood. Students may bring up Kochís postulates.
- Compare it to known pathogens to
see if it is a disease already characterized.
- Isolate antibodies from blood to
characterize particular antigens of the disease.
- Perhaps the Hepatitis B virus and
the wasting sickness virus are related?
- Isolate A is the chemical that cures
- This plantís isolate might
be used to treat breast cancer. It certainly should be investigated.
- Other cells, viruses, and bacterial
should be exposed to the isolates.
- Perform tests on laboratory animals;
toxicity, dosage, controls.
- Human trials in later stages.
- FDA approval
- Go to the village and surroundings
in South America to get leaves. Set up a factory that collects
leaves and refines extract.
- Do all work in South America or
ship extract to U.S.
- Use genetic engineering (recombinant
DNA) and forget the rain forest.
- Effect of "leaf mining"
on rain forest ecology.
- Do village people get any of the
- How abundant is the plant? Is
it widely distributed in the Amazon?